BUFFALO, N.Y. -- University at Buffalo researchers, working in
collaboration with University Health Network in Toronto, have
developed a novel contrast agent that could redefine what's
possible in the evolving field of medical imaging.

The contrast agent, called "porshe microbubbles," breaks ground
because it can be used jointly to create ultrasound images such as
a sonogram, and images from an emerging technology called
photoacoustic tomography (PAT). The result -- a more detailed,
nuanced picture of what's happening inside the body -- could help
doctors treat everything from hypoxia to cancer.

"We're only scratching the surface of what is possible," said
Jonathan Lovell, PhD, an assistant professor of biomedical
engineering at UB and co-author of "Porphyrin Shell Microbubbles
with Intrinsic Ultrasound and Photoacoustic Properties," which
appears on the Oct. 10 cover of the Journal of the American
Chemical Society.

Co-authors include Chulhong Kim, PhD, assistant professor of
biomedical engineering at UB; Mansik Jeon, PhD, postdoctoral
associate in biomedical engineering at UB; and four collaborators
from Toronto. To read the paper, visit: http://pubs.acs.org/toc/jacsat/134/40.

Doctors use ultrasound -- an effective, relatively inexpensive
and minimally invasive imaging technique -- for a variety of
purposes, including monitoring fetus development and blood flow in
the heart, liver and kidneys of children and adults. Doctors often
employ microbubbles, which are tiny bubbles of fluorinated gas
injected into a patient's bloodstream, to sharpen the grainy
black-and-white images produced from ultrasound.

PAT imaging, by contrast, is a much newer technique. Doctors use
pulsed laser lights to generate pressure waves that, when measured,
provide a more in-depth view of what's occurring inside the body.
For example, while ultrasound can measure blood flowing through an
organ, PAT can measure the oxygen levels in the blood.

Because the two techniques are complementary, there is growing
interest to combine them, Lovell said. The most likely way to
accomplish that would be to create "colored microbubbles," a
contrast agent that would sharpen ultrasound images and not
interfere with PAT imaging, he said.

Lovell, Kim, Jeon and others created such a contrast agent by
encapsulating microbubbles in a shell of porphyrin (an organic
compound that strongly absorbs light) and phospholipid (a fat
similar to vegetable oil). The result is porshe microbubbles.

"The early tests we've done look very promising. I think the
next step is to figure out how we can take advantage of this,
figuring out what the best applications are," Kim said.

One possibility entails using porshe microbubbles to analyze the
effectiveness of chemotherapy. Instead of waiting weeks for the
results, doctors could know within days, Lovell said. Another
potential use involves monitoring people who suffer from chronic
low blood oxygen levels, or hypoxia.

"We're really not sure how the technology will be used. We are,
however, confident it will be a very useful tool, especially in
medical imaging," Lovell said.